1. Field of the Invention
The present invention relates to a microscope capable of switching optical elements, such as objective lenses, from one to the other without disturbing operation posture for a focusing handle and a stage handle by operating an operation lever mounted near either the focusing handle or the stage handle, and to a microscope capable of preventing the objective lenses from coming into contact with a stage or a specimen when the objective lenses are switched.
2. Description of the Related Art
A microscope revolving nosepiece capable of switching objective lenses from one to the other without disturbing operation posture for a focusing handle has been developed. Such a revolving nosepiece includes a revolving-nosepiece body fixed to an underside of a lens barrel, a revolving-nosepiece rotating unit rotatably mounted on the revolving-nosepiece body and equipped with plural objective lenses, a knob arranged at a position near a focusing handle and distant from the revolving-nosepiece rotating unit and through which switching operation of the objective lenses is exerted, and a transmitting unit arranged between the knob and the revolving-nosepiece rotating unit and configured to transmit the switching operation of the objective lenses exerted through the knob to the revolving-nosepiece rotating unit.
The transmitting unit includes a rotation axis provided with the knob mounted on an end thereof, a drive pulley mounted on a base end side of the rotation axis, a driven pulley mounted on the revolving-nosepiece rotating unit, and a belt wound around the drive pulley and the driven pulley. Therefore, switching operation of the objective lenses is entered from the knob as rotation operation, and the entry of the rotation operation is transmitted from the drive pulley to the revolving-nosepiece rotating unit via the belt (see Japanese Patent Application Laid-open No. H8-220443).
Meanwhile, a microscope configured to switch objective lenses from one to the other by manual operation includes a click mechanism arranged between a revolving-nosepiece body and a revolving-nosepiece rotating unit so that the objective lenses can be accurately set (positioned) at stop positions. As shown in FIG. 5, a click mechanism 14 includes, for example, a click 15 mounted on the revolving-nosepiece body and a ball 16 mounted on the revolving-nosepiece rotating unit 12. The click 15 is a leaf spring mounted on a top surface of the revolving-nosepiece body and is structured such that both side edges 15a are obliquely bent so that the ball 16 can be put in from both sides and a groove 15b in which the ball 16 is to be fitted is arranged in the center of the click 15. The ball 16 is a hemispherical projection formed on a top surface of the revolving-nosepiece rotating unit 12 so as to correspond to the stop positions (switch positions) of the objective lenses. When the objective lenses are switched from one to the other, the ball 16 that has been fitted in the groove 15b of the click 15 is released from the groove 15b of the click 15, and then the ball 16 coming next is put in the click and fitted in the groove 15b of the click 15.
The microscope including the knob mounted near the focusing handle as described above is structured so that the objective lenses can be switched from one to the other by manual operation. Therefore, this microscope also includes the click mechanism 14. Thus, when the objective lenses are switched from one to the other by rotating the knob, the ball 16 that has been fitted in the groove 15b of the click 15 is released from the groove 15b of the click 15, and then the ball 16 coming next is put in the click 15 and fitted in the groove 15b of the click 15.
Japanese Patent Application Laid-open No. 2010-33025 discloses an inverted microscope in which a revolving-nosepiece operating unit, which is generally disposed under a stage and is thus not easily operable, is disposed near a focusing handle that is disposed at an easily operable position, and the magnitude of operating force of the revolving nosepiece is averaged to reduce the maximum magnitude of the operating force to thereby improve operability.
Furthermore, Japanese Patent Application Laid-open No. 2000-338417 discloses a structure in which a stage is stoppable at a predetermined position in a vertical direction only by pushing the stage downward, so that a specimen can be changed without contact with objective lenses even when the working distance of the objective lenses is short.
Moreover, Japanese Patent Application Laid-open No. S59-104616 discloses a microscope that includes an eccentric member disposed between a focusing transmission device and a stage holder so that a specimen can be moved quickly by the eccentric member.